System for attitude control and stabilization of a marine craft

ABSTRACT

A system for attitude control and stabilization of a marine craft includes at least one elongate substantially planar surface, which may be rigid or flexible, disposed on either side of and in substantial alignment with a bottom of the planing hull of the marine craft. The elongate surface, in a rigid form, includes a tongue-like distal end confined within a fluid hinge enclosure upon a region of the hull about 2 to 8 feet forward of the transom. In a flexible form, a distal end of the elongate planar surface is secured directly to the hull. The elongate surface further includes an actuation portion proximal to a transom of the craft. The system also includes an actuator selectably slidable and securable within an actuation sleeve, the sleeve secured to the transom of the craft. Also included in the system are elements, manual, hydraulic or electrical, for selectably advancing the actuator relative to the hull to induce a selectable angulation of the elongate planar surface relative the bottom of the hull of the craft.

FIELD OF THE INVENTION

The present invention relates to an improvement in classical trim-tabtechnology to enhance the general hydrodynamic performance of a marinecraft inclusive of the fuel efficiency thereof.

BACKGROUND OF THE INVENTION

So-called boat leveling devices of the trim-tab type have been known formany years and various forms of them have been developed in an effort tomaximize attitude control, stability of the marine craft and generalhydrodynamic efficiency inclusive of decrease of flow velocity under thehull and fuel efficiency.

The prior art trim-tabs which typically are provided in pairs to enhancestability of the craft, is shown in FIGS. 1 and 2 herewith. Moreparticularly, FIG. 1 shows a traditional external trim-tab 2 of which isattached directly to transom 3 of a craft 100 and in which the attitudeof the trim-tab is controlled through a hydraulic piston assembly 4which controls relative angulation of the hull relative to level of thewater. Also shown in FIG. 1 is a servo-loop wiring 9 by which assembly 4are controlled.

The prior art shown in FIG. 2 differs from that of FIG. 1 only in thatthe trim tab 2 is positioned beneath stern 6 of the craft 100 andforward of propeller 8. Therein, the direction of assembly 4 andhydraulic piston 5 are aligned with the gravity vector as opposed to theangled position of the hydraulic assembly shown in the prior art of FIG.1.

In general trim-tabs of the prior art, whether double or single acting,will operate upon the same principles and have a common objective,namely, that of contributing to the efficiency control of the boat'sattitude, stabilization and general hydrodynamics.

In recent years, most efforts of the prior art have been directedprimary to improvement of the electronics and the development ofalgorithms to optimize trim-tab control under various conditions ofvehicle speed, wave conditions, shape of the boat's hull, havingdistribution in craft, and other hydrodynamic considerations. The priorart also has experimented with the efficiency of electric motor controlsof the trim tabs as opposed to that of the hydraulic systems shown inFIGS. 1 and 2. In general, the durability of electric motor controls hasproven to be superior than that of hydraulic actuators.

The U.S. Navy has undertaken significant research and development inthis area to attempt to maximize performance of a variety of its boatsand, typically, of the types employed by the U.S. Coast Guard. In Navyterminology, a trim-tab is referred to as a stern flap, apparentlybecause its engineering objectives are more ambitious than are the casewith a leisure class powerboat. More particularly, the Navy hasidentified the following criteria as hydrodynamic mechanisms whichaccount for improved boat performance based on optimized stern flapdesign.

After body flow modifications:

-   -   Flow velocity under the hull decreased.    -   Pressure recovery increased.    -   Transom exit velocity increased.

Wave system modifications:

-   -   Localized transom system wave system altered.    -   Near field wave heights reduced.    -   Far field wave energy reduced.

Secondary stern flap hydrodynamic effects:

-   -   Ship length increased.    -   Beneficial propulsion interactions.    -   Ship trim modified (bow down trim induced).    -   Ship sinkage is reduced.    -   Lift and drag forces developed on flap.

The within inventor has recognized that the fundamental objectives andbenefits of trim tabs and stern flaps may be more effectively achievedif the entire length of the trim-tabs or stern flaps are extended. Andthat, when properly actuated and controlled, such elongated attitudecontrol element, as suggested can accomplish and substantially improveupon the performance of prior art trim tabs and stern flaps regardlessof hydrodynamic conditions. The efficiency of the present invention maybe yet further improved the assistance of contemporary electroniccontrols and algorithms. The present invention also improves uponefforts that seek to improve the performance of trim tabs thereofthrough modification of their geometry as, for example, is reflected inU.S. Design patent No. 292,392 (1987) to Zepp, entitled Boat LevelerTwin Tab.

SUMMARY OF THE INVENTION

The instant invention relates to a system for attitude control,inclusive of stabilization of a marine craft. The system includes atleast one elongate substantially planar surface disposed on either sideof and in substantial alignment with or parallel to a bottom of theplaning hull of the craft. In a rigid embodiment, said elongate surfaceincludes a tongue-like distal end confined within a fluid hingeenclosure upon a region of the hull at about 2 to 8 feet forward fromthe transom. In a flexible embodiment, the distal end of said elongatesurface is secured directly to the hull. The system further includes anactuator proximal to a transom of the craft, in which the actuator urgesagainst the elongate planar surface downwardly relative to the plane ofhull. The actuator is selectably slidable and securable within anactuation sleeve, the sleeve secured to the transom of the craft.Further included in the system are means, either manual, hydraulic orelectrical, for selectably positioning the actuator relative to thesleeve to induce a selectable angulation of a proximal portion of theelongated planar surface to thereby adjust the plane of said elongateplanar surface relative to a plane defined by the bow-to-stern of thecraft.

It is accordingly an object of the present invention to provide animproved trim tab system which overcomes the various hydrodynamiclimitations of the prior art, the same having utility with leisure aswell as naval vessels.

It is another object of the invention to provide a trim tab systemcapable of inducing a greater change in bow-to-stern or glide angleangulation of the marine craft relative to the water level whileincreasing the fuel efficiency thereof.

It is a yet further object to provide a system of the above type whichfurnishes improved accuracy of adjustment versus prior art trim tabstern flap systems.

It is a further object to provide a system of the above type havingutility in improved performance of marine craft whether used in a singleor double trim tab context.

It is a still further object to provide a system to improve the degreeand control of the glide angle of the watercraft and its ability tocorrect uplift zones to facilitate a more favorable weight distribution,each resulting in reduced fuel costs.

The present invention also seeks to reduce the need for submersible flowinterceptors as they are know in the art.

The present invention therefore seeks to provide more effective trimmingcoupled with the greatest possible uplift and lowest water resistancevalues, both at slow and high speeds, in a manner that does notsubstantially complicate the kinematics of prior art attitude controlsystems.

The above and yet other objects and advantages of the present inventionwill become apparent from the hereinafter set forth Brief Description ofthe Drawings, Detailed Description of the Invention and Claims appendedherewith.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one form of prior art trim tab system

FIG. 2 is a schematic view of a second form of prior art trim tabsystem.

FIG. 3 is a schematic side elevational view showing one embodiment of mysystem including its glide angle adjustment capability.

FIG. 4 is a stern end view of the illustration of FIG. 3.

FIG. 5 is a perspective schematic partial exploded view of the presentsystem installed upon the hull and transom of a marine craft.

FIG. 6 is a view, generally similar to that of FIG. 3, however showingthe flexible tab embodiment of my system.

FIG. 7 is a view generally similar to that of FIG. 6 showing anextension of the actuator.

FIG. 8 is a top perspective view of the system of FIGS. 6 and 7.

FIG. 9 is a perspective view of the system of FIGS. 3 and 4.

FIG. 10 is an exploded view of the system of FIGS. 3, 4, and 9.

FIG. 11 is a perspective view showing a third embodiment in which apower actuator is used with a flexible tab element.

FIG. 12 is a view generally similar to FIG. 11 but showing a manualactuator in combination with a power actuator and a flexible tab.

FIG. 13 is a view generally similar to FIG. 12 but showing the systemthereof with a rigid tab.

FIG. 14 is a perspective view of a power actuator used with a manualactuator, both with a rigid tab.

FIG. 15 is a perspective view showing or a manual actuator disposedbetween power actuators.

FIG. 16 is an exploded view showing two separate types of fluid hingeassemblies.

FIG. 17 is a side plan view of the embodiment of FIGS. 3, 4 and 10.

FIG. 18 is a sequential view showing the operation of the actuation ofthe tab of the system of FIG. 17.

FIG. 19 is an enlarged view of the fluid hinge portion of FIG. 17.

FIG. 20 is a perspective view of the bottom of the fluid hinge assembly.

FIG. 21 is a rear elevational view of the first embodiment of theactuator of my system when installed upon a transom of a marine craft.

FIG. 22 is a rear elevational view of the planning surface and fluidhinge receiver of my system installed upon the stern area of the hull ofa boat.

FIG. 23 is a perspective view of the power actuator of FIGS. 11 and 12,however showing a fixed pivot proximal end connection to a flexible tab.

FIG. 24 is a view, similar to that of FIG. 23, but showing another formof securement of the power actuator to the transom.

FIG. 25 is a lower perspective view of the manual actuator of FIGS. 3-5including a flexible tab having sidewalls and clip connectors at thedistal end of the tab.

FIG. 26 is a vertical cross-sectional view of FIG. 25 showing the mannerof engagement of the clip connectors with complemental elementsdepending from the bottom of the hull of the boat.

FIG. 27 is an enlarged view of the circled portion of FIG. 26.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the schematic views of FIGS. 3-4, the stern andmid-hull elements of a first embodiment the invention are shown. Moreparticularly, a craft may be seen to include a hull 20 and transom 3 towhich is secured a vertical plate 22 which extends downward and behindan actuation sleeve 30. Within actuation sleeve 30 is actuator 28 whichurges downwardly against an elongate planar attitude control surface,also referred to herein as tab 26. It may be seen in FIGS. 3, 5, 9 and10. The attitude control surface may be either rigid or flexible, theflexible surface indicated as element 126, in FIGS. 6-8 and 10-11.

In the manually operated embodiment of the present system, handle 29 isemployed to advance actuator 28 downward to a desired aperture 46 atwhich a transverse bar portion of the handle is employed to establish afixed location tab 26 below the keel of the boat. Typically, saidsurface is adjustable in a range of about zero to at least 15 degreesrelative to the keel of the boat, this is may be seen in FIGS. 3, 6 and8. The structure of FIG. 4 may be seen in exploded view in FIG. 10. Thetab or elongate planar attitude central surface 26 more particularlyincludes a distal tongue element 39 which is held by a fluid hingereceiver 41 which is secured at a distal area to keel 20 of the boat.Thereby, as for example is shown in FIGS. 7-8 and 17-19, said elongatesurface 26 is held to the hull 20 by rivets 134 to assure stability ofthe receiver 41.

In a preferred embodiment, said tabs 26 are provided with downwardlydirected sidewalls 40 (see FIGS. 9-10) which operate to enhance thestability of the present attitude control system. Said embodiment may,in certain applications, define a length of about 30 inches but, inother embodiments (see for example FIG. 11), may be much shorter. Anelongate and flexible portion 126 of intermediate length is shown in theembodiment of FIG. 12. As may be noted, sidewalls 40 are not required inthe flexible tab embodiment.

In accordance with the present invention, there are taught two basicembodiments of elongate planar attitude central surface 26, namely, therigid embodiment as is shown in FIGS. 3, 5, 9, 10, and 13-16, and theflexible embodiment which is shown in FIGS. 6, 8, 11 and 12. It is to beappreciated that in both elongate embodiments, the proximal portion 125may operate with any combination of types of actuators, as is more fullydescribed below.

With reference to FIG. 6, it is to be appreciated that in the flexibletab embodiment a distal end of planar structure 132 may be inlayeddirectly into the hull 20 of the boat, in which case a securing plate134, held by bolts 133 or the like, is employed.

FIG. 6 also shows the manner in which vertical actuator sleeve 30 may besecured to transom 13.

In the present invention, the curvature of distal end 128 of actuator 28plays an important role in the functioning of the attitude controlsurface 126, particularly in the flexible plate embodiment of theinvention. More particularly, as may be seen in FIGS. 6, 7, 8, and 10,the surface at end 128 is rounded to facilitate ease of contact withsurface 126 with a minimum of friction against distal end 128 and uponsaid surface 126.

Further, actuator 28 may freely engage proximal portion 125 or, as isshown FIGS. 4, 5, and 8-10, may be secured to said surface of theattitude control member by brackets 25 which are held to the distal end128 of the actuator 28 by axle 36. See FIG. 8.

The present system also contemplates the selectable use of poweractuators 130 (see FIGS. 11-15) which may be employed either separatelyor in combination with manual actuators as set forth above and shown inFIGS. 3-10. In many applications as, for example, is shown in FIGS.12-15, it is useful to employ one or more power actuators in combinationwith a manual actuator. Therein, a single manual actuator is placedbetween two power actuators, that is, may be placed at either side of amanual actuator and held by plate 122, as is shown in FIGS. 13 and 15.FIGS. 12 and 14 illustrate use of a power actuator 130 secured in frontof a manual actuator 28 in respective flexible and fixed tab embodimentsof the invention. More particularly, in FIG. 14 is shown power actuator130, having extensible element 138. secured to manual actuator 28 by ametal band 129 which attaches to transom plate 22. Both actuators restupon plate 125.

As may be appreciated, each power actuator, regardless of how employed,includes said extensible element 138 at an end of the power actuator 130which uses internal means for power extension that may be eitherhydraulic or electrical. This strategy may be seen with reference to theembodiments of FIGS. 12 and 13. Therein, if one wishes not to use themanual actuator, handle 31 thereof may simply be placed in a topmostposition as for example is shown in FIGS. 12-15. Therein, the weight ofgravity will assist power actuator 130 in its downward urging ofproximal portion 26 of elongate attitude control surface 24.

Where two power actuators 130 and 130A are employed, one may employbrackets 125 secured to distal end 128 of the manual actuator toequalize the effect of possibly unequal extensions between elements 138of each power actuator that otherwise might cause an imbalance upon theproximal portion 26 of elongate attitude control surface 24. See FIG.15.

FIG. 16 is an exploded view of two embodiments of the receiver of thepresent invention in which clip tabs 42 may be attached at the distalend 39 of attitude control surface 24. Alternatively, lateral elements142 of receiver 41 may be secured to hull of the boat in the mannershown in FIGS. 17 to 19 in which provide a more detailed view of theembodiment of FIGS. 3-5 in which the downward rotation of rigid attitudecontrol surface 24 may be seen and, therewith, the extension of theactuator downwardly against proximal portion 26 of elongate planarsurface 24. Therein may be seen the manner in which vertical distalsurface 47 of elongate surface 24 facilitates insertion of its tongueelement 39 into fluid hinge receiver 41 which in turn is secured to hull20 of the boat. In other words, an hinge effect is accomplished by thestructure shown in FIG. 18 while proximal end 26 of elongate planarelement 24 is able to rotate downwardly with the distal end of actuator28 upon axle 36 to a depth in a range of about four to ten inches and toan angle of up to at least 15 degrees. An enlarged view of the hingearea of FIG. 18 is shown in FIG. 19.

In FIG. 20 is shown a bottom perspective view of fluid receiver 41 shownin FIGS. 5, 8 10 and 15-19

In FIG. 21 is illustrated the attachment of a manual embodiment of thepresent system, with one unit attached at opposite sides of keel 7 ofthe marine craft across the transom 13 thereof.

In FIG. 22 is shown the location of receivers 41 which may be secured tobow 15 of the marine craft by elements 150.

It is to be further appreciated that the actuator assembly, as abovedescribed, may be positioned and secured internally to the hull in themanner shown in FIG. 2 or lower within the hull. Therein, the actuatoris extensible beyond the keel of the boat to the proximal portion of theelongate planar surface 26.

FIG. 23 is a view of the power actuator 130 of FIGS. 11 and 12 in whichproximal end 138 thereof is rotatably secured by axle 136 withinbrackets 125 of forward end 124 of flexible tab 132A. Also shown istransom plate 122, extension plates 132 and 134 of actuator 130 and axle132 therebetween. A metallic strip 129 holds actuator 130 to transomplate 122.

FIG. 24 is a view, generally similar to that of FIG. 23, in which thereare provided protective housings 222 and 222A which include axle 229therebetween upon which distal element 224, depending from poweractuator 130 may rotate while securing a distal end of the actuator 130.Also, in FIG. 23, proximal end 138 of the actuator is rotatably securedto forward end 124 of flexible tab 132A by brackets 125 and an axle 236between said brackets.

FIG. 25 is a lower perspective view showing a manual actuator 28 of thetype of FIGS. 3-5 including guide and sidewalls 40 depending fromforward end 26 of tab 232A. However, unlike the embodiment of FIGS. 3-5,tongue and receiver elements 39/40 thereof, are replaced by quickconnect prongs 242, depending from tab 232A, which are held bycomplemental female elements 241 within the hull. See FIG. 26. Alsoshown in FIG. 25 is actuator guide assembly 22.

FIG. 26 is a vertical cross-sectional view of the embodiment of FIG. 25,showing the manner in which prongs 239 engage female elements 241 of tab232A. Proper positioning and securement of prongs 239 is assured by theprong 239 depending from bolts 243 which are secured to hull 20 byplates 245 and 246 and associated lock nuts 247. This arrangement isshown in enlarged view in FIG. 27. Therein a full range of motion of tab261/232A relative to hull 20 may be achieved as is shown to the right ofFIG. 26. The actuator guide 22 is secured to transom 13 by actuatorplate 22A. Also shown therein is actuator 28 and lower brackets 225 towhich tab 26/232A is rotatably secured as discussed above regarding FIG.18.

While there has been shown and described above the preferred embodimentof the instant invention it is to be appreciated that the invention maybe embodied otherwise than is herein specifically shown and describedand that, within said embodiment, certain changes may be made in theform and arrangement of the parts without departing from the underlyingideas or principles of this invention as set forth in the Claimsappended herewith.

1. A system for attitude control and stabilizing of a marine craft, the system comprising: (a) at least one elongate substantially planar surface disposed substantially in parallel with a bow-to-stern axis of one side of a bottom of a hull of the marine craft, said elongate planar surface further including a proximal actuatable portion at a stern end of said planar surface, said proximal portion extending from beneath said hull to beyond a transom of the craft; (b) an actuator slidably positionable within a substantially vertical containment sleeve, said sleeve secured to a transom of said marine craft, a lower end of said actuator in selectable contact with said proximal portion of said elongate planar surface; (c) means for selectably advancing said actuator within said sleeve against said proximal portion of said planar surface to define a planing angle of said elongate planar surface relative to said one side of said hull of the marine craft to which it is secured; and (d) distal end of said elongate planar surface defines a tongue-like geometry confined within a fluid hinge defining enclosure secured upon said hull of the craft.
 2. The system as recited in claim 1, in which a range of adjustment of said elongate planar surface relative to the axis of the bottom of the hull of the marine craft is in a range of about zero to at least 15 degrees.
 3. The system as recited in claim 1, further comprising a stop limit to preclude over extension of said actuator relative to said actuation sleeve.
 4. (canceled)
 5. The system as recited in claim 1, in which a transverse cross-section of said actuator and sleeve each define a square or rectangle.
 6. The system as recited in claim 1, in which a traverse cross-section of said actuator and sleeve each define a circle.
 7. The system as recited in claim 9, said elongate planar surface comprises: downwardly directed integral side edge elements substantially along an entire length of said elongate planar surface.
 8. The system as recited in claim 3, in which a transverse cross-sectional of said elongate planar surface defines an inverted letter “U” at the proximal region of said elongate surface.
 9. The system as recited in claim 1, in which said elongate planar surface comprises a rigid material.
 10. The system as recited in claim 1, in which said elongate planer surface comprises a flexible material, a distal end of said surface rigidly secured to said hull of the vessel.
 11. The system as recited in claim 1, in which said actuator comprises a power actuator.
 12. The system as recited in claim 1, in which said actuator comprises one or more manual and hydraulic actuators mounted together with each other.
 13. (canceled)
 14. The system as recited in claim 1, in which said fluid hinge defining enclosure defines a location of between about 2 feet and about 8 feet forward of the transom.
 15. The system as recited in claim 3, in which said distal end of said elongate planar surface includes male elements proportioned for complemental engagement of female elements depending from an opposing surface of the hull of the marine craft.
 16. The system as recited in claim 8, in which said distal end of said elongate planar surface includes male elements proportioned for complemental engagement of female elements depending from an opposing surface of the hull of the marine craft. 